1. Field of the Invention
The present invention generally relates to a camera, and particularly relates to a mechanism for controlling a flash light emission of the camera. The present invention also relates to a method for controlling the flash light emission.
2. Description of the Related Arts
Conventionally, there have been proposed a variety of cameras each of which is able to photograph a subject (i.e. an object to be photographed) while emitting a flash light from a flash gun of the camera under a condition in which there is set a predetermined contribution rate for each of a plurality of light adjustment fields (or regions) that are formed by dividing a photographing field (or region). According to such a camera, a light adjustment control (or a control of the emission of the flash light) is performed as follows.
That is, as shown in FIG. 3 for example, an OUTPUT DEVICE FOR INFORMATION UPON SUBJECT S2 detects a location of a main subject to be photographed, a distance up to the main subject, a state of the background, and so forth, on the basis of a photometric value which is optically measured by a MULTI-DIVISION PHOTOMETRIC DEVICE S6, and on the basis of a focusing value which is measured by a FOCUSING DEVICE S7, in order to execute the light adjustment control. A CALCULATOR FOR CALCULATING CONTRIBUTION RATE OF LIGHT ADJUSTMENT S3 calculates a contribution rate of light adjustment, for example, on the basis of information upon the main subject detected by the OUPTPUT DEVICE FOR INFORMATION UPON SUBJECT S2, and on the basis of a photometric value which is optically measured by preparatorily making the flash gun emit the flash light by a PREPARATORY LIGHT EMISSION MONITOR S8. A LIGHT ADJUSTMENT CONTROL DEVICE S4 controls a MULTI-DIVISION LIGHT ADJUSTMENT DEVICE S5 on the basis of the contribution rate of light adjustment which is calculated by the CALCULATOR FOR CALCULATING CONTRIBUTION RATE OF LIGHT ADJUSTMENT S3, so that the contribution rate is set for each light adjustment region or field.
According to the mechanism, the light adjustment control is executed by calculating the contribution rate of light adjustment in accordance with a specified algorithm on the basis of the results of photometry (or photometric measuring), focusing operation and preparatory light emission.
However, in order to improve the performance, or ability, of the flash exposure, there is need of increasing the number of light measuring points and/or increasing the number of focusing points and/or complicating the algorithm, so that the time of calculation or operation required for the light adjustment algorithm, and/or the time of control required for the light adjustment, become(s) longer.
On the other hand, conventionally, there have been proposed a variety of cameras in each of which it is possible to take a photograph while making a flash light emit from a flash gun with a state in which the amount of flash light is controlled in accordance with a photographing condition. Such a camera has a construction as follows.
That is, as shown in FIG. 39 for example, an OUTPUT DEVICE FOR INFORMATION UPON SUBJECT POSITION S25 of the camera detects a location of a main subject to be photographed, a distance up to the main subject, a state of the background, and so forth, on the basis of a photometric value which is optically measured by a MULTI-DIVISION PHOTOMETRIC DEVICE S6, and on the basis of a focusing value which is measured by a FOCUSING DEVICE S7. A CALCULATOR FOR CALCULATING COMPENSATION VALUE OF LIGHT ADJUSTMENT S30 detects a compensation value for light adjustment, on the basis of information, detected by the OUTPUT DEVICE FOR INFORMATION UPON SUBJECT POSITION S25, upon the subject to be photographed. A LIGHT ADJUSTMENT CONTROL DEVICE S4 controls an amount of flash light emission, on the basis of the compensation value for light adjustment which is calculated by the CALCULATOR FOR CALCULATING COMPENSATION VALUE OF LIGHT ADJUSTMENT S30.
According to the mechanism, the light adjustment control is executed by calculating the compensation value for light adjustment in accordance with a specified algorithm on the basis of the results of photometry (or photometric measuring) and focusing operation.
However, in order to improve the performance, or ability, of the flash exposure, there is need of increasing the number of light measuring points and/or increasing the number of focusing points and/or making preparatorily the flash light emit from the flash gun, so that the algorithm becomes complicated. Namely, accompanying the complication of the algorithm, the time of calculation or operation required for the light adjustment algorithm, and/or the time of control required for the light adjustment, become(s) longer.